Doing some research on how we can implement this type of system with ethereum smart contracts.

Currently the upcoming Nxt/Ardor system implements a child chain system where the main chain deals with finding of the blocks while the child chain does the collection of the transactions and paying for the fees by the child chain genesis account.

Take for example if we were to create a blockchain just to sell concert tickets, each user would currently need to pay "ether" to send these concert tickets to another user. But how would one create a similar system to Ardor where there is a parent and child chain?